Implementation of Discrete Crack Modelling for the Conservation Interpretation of Hagia Sophia

Hagia Sophia has exceptional dimensions, complex load-transfer paths, and a long seismic history. This study examines crack initiation and propagation in its principal structural system under vertical loading, with the aim of identifying structurally critical regions that may inform future conservation and strengthening interventions. It focuses on M2, a reduced model of the main dome, semidomes, arches, pendentives, and piers. M2 used a discrete crack procedure under a vertical loading. A vertical self-weight multiplier (λ) began at 0.8 and increased in 0.2 increments. At each stage, principal stresses were checked against the strength limits used in the original study. Cracked parts were separated at shared nodes. Fully cracked portions were removed, and the same load level was re-analysed until crack development stopped. Cracking first appeared at the semidome-to-arch connections and then progressed through the piers and dome. At λ = 1.8, rapid dome cracking produced the adopted numerical collapse condition. The results are discussed alongside buttressing, consolidation, ties, and dome-level hooping.